The design of marine craft, conventionally employs a hull which is designed to ride in the water in only one orientation, that is to say with its keel or center portion of the hull lowermost, and with the sides of the hull projecting above the water. The crew, passengers, cargo, etc. are intended to be contained within the hull.
In smaller craft the hull is simply open, and in larger craft a deck conventionally covers in the open upper portion of the hull.
Structure within the interior of the hull is normally fixed to the hull. When the hull rolls, any structure attached within the hull will, of course, roll with it. The design of ships lifeboats and other rescue craft has followed these lines. As a result, passengers and crew attempting to leave a vessel in distress are required to climb into what is essentially an open boat, which is then lowered by ropes into rough water immediately alongside the rolling vessel, after which the ropes are cast off, and an attempt is made to propel the lifeboat either with oars or under power away from the side of the sinking vessel.
It is well known that this is a most hazardous undertaking, and that it is almost never practiced in rough weather, and that in all probability more lives are lost attempting to leave a vessel than would be lost if they remained on board. Other forms of life-saving craft involve life rafts, and inflatable craft. Life rafts are generally speaking unsuitable since persons on them are totally exposed to the elements.
In addition, in rough weather a life raft may tumble over and over, and it is almost impossible for a person to maintain his grasp in those circumstances. Inflatable rafts are provided having complex designs incorporating inflatable canopies or hoods. These inflatable craft do not appear to be entirely satisfactory. Experience of persons attempting to use them in rough weather indicates that they too are easily overturned. In addition, the rough handling likely to be experienced during an escape from a sinking vessel in rough weather is likely to puncture the craft or damage the fabric of such inflatable craft rendering them useless.
Lifeboats may be constructed with decks to enclose the hull but this is generally impractical. Such craft must be small enough to be carried on a larger vessel, and launched from it.
Hull design conventionally requires an outer skin, and an inner frame work of ribs, which support the outer skin. Where the hull is to be totally enclosed with a deck, the construction of the deck will have to follow the same general principle, that is to say, it will have to incorporate an outer skin, and ribs extending across its interior.
This will severely restrict the space available in the interior of the hull, and the seating accommodation will be limited.
Even when fully decked-in, such a lifeboat could be capsized in rough weather, and while it might continue to float, it would be unmanageable and endanger the occupants.
Some of these considerations also apply to craft other than life saving or emergency craft.
Sports and pleasure craft may well utilize aspects of the invention with advantage.